review comments

internal/fs/fs.go

@@ -1832,9 +1832,12 @@ func (fs *fileSystem) RmDir(
 			err = fmt.Errorf("ReadEntries: %w", err)
 			return err
 		}
-		//Clear kernel list cache after removing a directory. This ensures remote
-		//GCS files are included in future directory listings for unlinking.
-		childDir.InvalidateKernelListCache()
+
+		if fs.kernelListCacheTTL > 0 {
+			// Clear kernel list cache after removing a directory. This ensures remote
+			// GCS files are included in future directory listings for unlinking.
+			childDir.InvalidateKernelListCache()
+		}
 
 		// Are there any entries?
 		if len(entries) != 0 {

internal/fs/inode/base_dir.go

@@ -243,7 +243,7 @@ func (d *baseDirInode) ShouldInvalidateKernelListCache(ttl time.Duration) bool {
 	return true
 }
 
-// Kernel list cache is not supported for baseDirInode.
+// List operation is not supported for baseDirInode.
 func (d *baseDirInode) InvalidateKernelListCache() {}
 
 func (d *baseDirInode) RenameFolder(ctx context.Context, folderName string, destinationFolderId string) (op *gcs.Folder, err error) {

internal/fs/inode/dir.go

@@ -147,8 +147,8 @@ type DirInode interface {
 	// should be invalidated or not.
 	ShouldInvalidateKernelListCache(ttl time.Duration) bool
 
-	//InvalidateKernelListCache sets the prevDirListingTimeStamp to zero so that
-	//cache is invalidated for next list call.
+	// InvalidateKernelListCache guarantees that the subsequent list call will be
+	// served from GCSFuse.
 	InvalidateKernelListCache()
 
 	// RLock readonly lock.

internal/fs/inode/dir_test.go

@@ -1572,6 +1572,7 @@ func (t *DirTest) TestRenameFolderWithNonExistentSourceFolder() {
 func (t *DirTest) Test_InvalidateKernelListCache() {
 	d := t.in.(*dirInode)
 	d.prevDirListingTimeStamp = d.cacheClock.Now()
+	AssertFalse(d.prevDirListingTimeStamp.IsZero())
 
 	t.in.InvalidateKernelListCache()